JPH0242541A - Abnormality display device for office equipment - Google Patents

Abstract

PURPOSE:To protect a display device at occurrence of the abnormality and to display the occurrence by de-energizing the display means and informing the occurrence of the abnormality via an abnormality display means after detection of the abnormality of a slave control unit which controls many display means. CONSTITUTION:Many display devices contained in a display unit 220 of a control board 220 are connected to each other in a matrix form which is divided into plural row and columns. Then only the display device connected to a designated row corresponding to the scan signal produced by a microcomputer 210 is turned on. Then the designated rows are successively switched via the dynamic display control. Here the energization is cut to all display devices when the working of the microcomputer 210 is stopped. Therefore all displays are turned off on the board 220 except an abnormality display LED when a main control board 100 detects the abnormality of the board 220. Thus only the display LED is turned on.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to display control of office equipment such as copying machines, and particularly to display control when an abnormality occurs in office equipment equipped with a plurality of mutually independent control units such as microcomputers. Regarding control.

[Prior Art] Many office equipment 9, such as copying machines, facsimile machines, printers, etc., are equipped with a microcomputer (hereinafter referred to as CPU) as a control device, and especially recently, one device has three or more CPUs. It is not uncommon for some to be equipped with the following.

Incidentally, in a CPU or the like, there is a possibility that a phenomenon called a runaway occurs in which an abnormal operation that is completely different from the contents of a normal program occurs. - If a runaway occurs, normal operation cannot be restored unless a reset signal is applied to return the program execution to its initial state.

Therefore, conventionally, in devices using a CPU, the presence or absence of runaway has been monitored by the following method.

(1) Use dedicated hardware such as a watchdog timer to monitor pulse signals periodically output by the CPU.

(2) C: A pulse signal periodically output by the PU is monitored by another CPU.

By the way, in this type of device, when an abnormality is detected, numerically speaking, a reset signal is applied to the CPU to reset the CPU.
It controls to initialize the operation of the PU.

[Problems to be Solved by the Invention] By the way, when controlling a large number of display devices, 1. Usually, in order to reduce hardware costs, they are connected in a matrix and one of the display devices divided into multiple groups is connected. So-called dynamic display control is often performed in which only one group is energized and the energized groups are sequentially switched. Furthermore, in dynamic display control, in order to increase the contrast of the display, the current flowing through the display is set to be much larger than in the case of static display control. In other words, in dynamic display control, the energization duty of each display is small, so even if a current larger than the rated current is applied to increase the contrast, the average current flowing to each display can be smaller than the rated current, so each display There is no risk of it being destroyed.

However, in a device that performs dynamic display control, if an abnormality occurs and the energization control is switched to static, an average current larger than the rated current will flow through the energized display.

The display will be destroyed.

For example, since there are many displays on the operation board of a copying machine, many of them are connected in a matrix and the display is controlled dynamically by the CPU.
If the CPU goes out of control in this type of device, the periodic switching of the energized display will stop, so only some of the displays will remain energized, resulting in a static display. , If left as is, the display while it is energized will be destroyed.

Generally, when a runaway occurs in this type of equipment, C
It is preferable to stop the PU and cut off the power supply to the load.
However, in the case of an operation board, when the CPU is stopped, the indicator on the silkworm turns off, making it impossible to indicate the occurrence of an abnormality. Another possible method is to apply a reset signal to the CPU to initialize program execution when a runaway occurs.

However, if a runaway occurs due to some kind of failure and a reset signal is applied, the CPU will repeat the runaway, and each time an excessive current will flow through the display, causing stress to accumulate on one display and causing it to break down. There is a high possibility that it will be done.

The present invention protects a display device that is subject to dynamic display control when an abnormality such as runaway occurs in the control device, and
The purpose is to enable display of abnormal occurrences.

[Means for Solving the Problems] In order to quickly achieve the above object, the present invention provides a slave device including a first control means and a plurality of display means connected in a matrix whose display is controlled by the first control means. An abnormality display device for office equipment, comprising: a control unit; and a master control unit, which includes a second control unit that performs control independent of the first control unit, and controls the entire device including the slave control unit: comprising an abnormality display means connected to the master control unit, and when the master control unit detects an abnormality in the slave control unit, the master control unit stops the first control means for the slave control unit; The abnormality display means is energized by applying a stop signal that de-energizes the display means.

[Function] In other words, a separate master control unit constantly monitors the status of the slave control unit that controls a large number of display means such as the operation board, and if an abnormality is detected in the slave control unit, a stop signal is sent to it. is applied to de-energize the display means, and at the same time, energizes the abnormality display means specially connected to the master control unit to notify the occurrence of an abnormality. According to this, there is no fear that the large number of display means connected in a matrix will be destroyed, and since the occurrence of an abnormality is displayed by the abnormality display means, it is possible to immediately know the failure of the apparatus.

In a preferred embodiment of the present invention, which will be described later, information is transmitted between a master control unit and a slave control unit, the time interval at which information is received is measured, and when the time interval exceeds a predetermined value, the sending side This is treated as an abnormality in the control unit.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

[Embodiment] FIG. 2 shows one type of copying machine embodying the present invention. This will be explained with reference to FIG. In summary.

This copying machine consists of a copying machine main body, an ADF (automatic document feeder) 60. Sorter 70. It is composed of a group of optional units such as an automatic double-sided processing unit 80. The paper feed system that supplies recording sheets has five stages. That is, the first paper feeding system and the second paper feeding system are provided in the main body of the copying machine, and the second paper feeding unit 170, which is the third paper feeding system, the fourth paper feeding system, and the fifth paper feeding system are provided in the main body of the copying machine.
A third paper feeding unit 180 including a paper feeding system is connected to the main body of the copying machine. 21, 22, 23 and 24 are cassettes provided in the first paper feeding system, second paper feeding system, third paper feeding system and fourth paper feeding system, respectively, and 25 is a tray of the fifth paper feeding system. be.

A contact glass 1 on which a document is placed is provided at the top of the copying machine body, and an optical scanning system 30 is provided below it.The optical scanning system 30 includes an exposure lamp 31.
Mirror 32. Third mirror 33° Fourth mirror 34. Lens 35. A fifth mirror is provided with a 36° slit 37, etc. When performing document reading scanning, the first
The carriage and the second carriage carrying the third mirror 33 and the fourth mirror 34 are mechanically driven for scanning at a relative speed of 2:1. The lens 35 is a zoom lens, and its magnification can be changed by driving a motor.

Therefore, the light emitted from the exposure lamp 31 is transmitted to the first mirror 32.
．． Third mirror 33. Fourth mirror 34. Lens 35. Fifth
Through the mirror 36 and the slit 37, the photosensitive drum 2
imaged on top.

Around the photoreceptor drum 2, there are a main charger 3 and an eraser 4. Developing device5. Pre-transfer static elimination lamp 6, transfer charger 7, separation charger 8. It is equipped with a dangling unit 9, etc.

The image reproduction process will be briefly explained. The surface of the photosensitive drum 2 is uniformly charged to a predetermined high potential by the discharge of the main charger 3. The charge in the portion not used for image reproduction is erased by the eraser 4. When the charged surface of the photoreceptor drum 2 is irradiated with reflected light from the original, the potential of that part changes (decreases) depending on the intensity of the irradiated light.
The photosensitive drum 2 rotates in the direction shown by the arrow in the figure.
In synchronization with this, the optical scanning system 30 sequentially scans the document surface, so that a potential distribution corresponding to the density (light reflectance) distribution of the document image, that is, an electrostatic latent image, is formed on the surface of the photoreceptor drum 2. Ru.

When the portion on which the electrostatic latent image is formed passes near the developing device 5,
The toner in the developing device 5 is attracted to the surface of the photoreceptor 2 according to the potential distribution, thereby developing an electrostatic latent image, and a visible image corresponding to the electrostatic latent image is formed on the photoreceptor drum 2. Ru. On the other hand, in synchronization with the progress of the copying process, recording sheets are supplied from one of the five paper feeding systems selected. This recording sheet is fed through the registration rollers 27 at a predetermined timing so as to overlap the surface of the photosensitive drum 2.

The transfer charger 7 transfers the visible image (toner image) on the photoreceptor drum 2 onto the recording sheet, and the separation charger 8 separates the recording sheet to which the visible image has been transferred from the photoreceptor drum 2. The six separated recording sheets are conveyed to a fixing device 12 by a conveyor belt 11. After passing through the fixing device 12, the toner image on the recording sheet is fixed onto the recording sheet by heat within the fixing device 12. The recording sheet that has been fixed is discharged to the sorter 70 or the automatic duplex unit 8o- through a predetermined paper discharge path.

FIG. 3 shows the appearance of the operation board arranged on the top surface of the main body of the copying machine shown in FIG. Referring to FIG. 3, this operation board has a large number of key switches Kl.

K2. 3. 4a, 4b, 5. 6a.

K6b, 7. 8. 9a, 9b, 9c.

K10. Kll, 12a, 12b, 13°KC,
KS, to #, Kl and KT and a number of indicators DI, D2
．． D3. D4. D5. Equipped with LED etc.

The indicator LED indicates when an abnormality occurs in the control system of this copying machine. Regarding the functions of other indicators and various key switches provided on the operation board,
Since this is well known, the explanation will be omitted.

Referring to FIG. 1, which schematically shows the configuration of the control system of the copying machine shown in FIG. 100 is a main control board, 200 is an operation board, and 300 is an optical system control board, and each board is equipped with an independent microcomputer 1.
10°210 and 310 are provided.

The microcomputer 210 of the operation board 200 has a display control circuit 230. Key switch matrix 240. Lamp control circuit 250. It is connected to the heater control circuit 260, etc., and controls the display of one display unit 220 (indicators Di, D2.D3°D4.D5 shown in FIG. 3), scans and reads the status of various key switches, and controls the exposure lamp 31. It performs dimming control, temperature control of the heater provided in the fixing device 12, etc.

Microcomputer 310 of optical system control board 300
is RAM (read/write memory) 320. Motor control circuits 330, 340. It is connected to a driver 360, etc., and performs reciprocating scanning drive control of the optical scanning system 30, copy image magnification control, image erasure control, etc. Ml is an electric motor that drives the optical scanning system 30, and Ml is an electric motor that adjusts the magnification of the lens 35 of the optical system. A battery is connected to the power supply circuit of the RAM 320, and the RAM 320 is configured to retain its stored contents even when the power of the copying machine is turned off.

The control elements of the copying machine other than those mentioned above, such as the main motor, paper feeding mechanism, conveyance mechanism, paper ejection mechanism, various image reproduction process elements, fans, various optional units, etc., are controlled by the microcomputer 110 of the main control board 100. Ru. Signals from the sensor group 130 provided in each part of the copying machine are applied to the microcomputer 110 via a signal processing circuit 180, respectively. Solenoid, clutch.

Loads such as fans are connected to the microcomputer 110 via a driver 190. The high voltage power supply unit 120 includes a main charger 3°, a transfer charger 7,
It is connected to the bias electrodes of the separation charger 8 and the developing device 5, and supplies a predetermined high voltage or current necessary for the image reproduction process to these electrodes at a predetermined timing.

In this embodiment, the high-voltage power supply unit 120 adjusts the voltage or current value by pulse width control (PWM), and the signal that determines this pulse width is generated by the programmable timer 160.

A RAM (read/write memory) 150 equipped with a battery backup circuit is connected to the microcomputer 110 . The RAM 150 stores numerical values for determining various voltages and currents generated by the high-voltage power supply unit 120, numerical values for setting the light amount of the exposure lamp, numerical values corresponding to the set temperature of the fixing heater, and the like.

In addition, the microcomputer 110 of the main control board
is connected to the microcomputer 210 of the operation board and the microcomputer 310 of the optical system control board via a serial communication line so that information can be transmitted to each other.
connected with them.

That is, the serial signal transmitting port TxD of the microcomputer 110 is connected to the serial signal receiving port RxD of the microcomputer 310 via the gated buffer Glb and buffer G3b, and is connected to the serial signal receiving port RxD of the microcomputer 310 via the gated buffer Gle and buffer G2c. , serial signal receiving port Rx of microcomputer 210
D, and is also connected to microcomputer 11
Serial signal receiving port RxD of 0 is connected to serial signal transmitting port TxD of microcomputer 310 via gated buffer G1c and buffer G3a, and also connected to gated buffer Glf and buffer G.
2b, it is connected to the serial signal transmission port TxD of the microcomputer 210.

The output of the microcomputer 110 is
It is connected to the gate terminals of buffers yG1b, Glc, Gle, and Glf, and when SEL is at a high level H, the gates of buffers Glb and G1c open, the gates of G1a and Glf are closed, and SEL is at a low level L. When , the gates of buffer Gl)) and Ole are closed and Ole and G
The lf gate is now open. Umari, SEL
When SEL is H, communication between microcomputers 110 and 310 is enabled, and when SEL is L, communication between microcomputers 110 and 210 is enabled.

The main control board 100 includes a reset IC (7) that generates a reset signal when the device power is turned on/off.
705) 195 is provided. Reset IC19
The signal (RESET) output by the microcomputer 5 is applied to each reset terminal of the three microcomputers 110, 210, and 310. Therefore.

The microcomputers 110, 210, and 310 always perform a reset operation when the power is turned on/off.

The display LED provided on the operation board 200 is as follows.

A light emitting diode, which is the main control board 100
The lighting and extinguishing of the light are directly controlled by the control signal ABN applied from the control signal ABN. Therefore, the control of the indicator LED is as follows:
It is controlled separately from the control by the microcomputer 210.

In this embodiment, the microcomputer 110°210
and 310, 7811G manufactured by NEC Corporation is used. FIG. 4 shows an outline of the internal configuration of this microcomputer. Referring to FIG. 4, this microcomputer includes an oscillation circuit OSC, a serial I10 circuit Bl, an interrupt control circuit B2. Timer circuit B3. Timer/
Event counter circuit B4. A/D conversion circuit B5. Register B6. EPROM memory B7. It consists of a RAM memory B8 and various control blocks necessary for other processing.

The serial I10 circuit B1 has a serial data input terminal R.
A transmitting section includes three terminals: xD, serial data output terminal TxD, and serial clock input/output terminal SCK, as well as an 8-bit serial register, a buffer register, and a transmission/reception control circuit (not shown).

It consists of a receiving section and a mode register that specifies the operating mode. Note that each terminal RxD, TxD and SCK is connected to port Pc1. It is shared with PCO and PO2.

The transmitting buffer register generates an interrupt request INTST when internal data becomes empty, and the receiving buffer register generates an interrupt request signal INTSR when the internal data is fully stored.

The three microcomputers 110°210. in FIG.
The outline of the data transmission procedure performed between 310 and 310 is shown in
As shown in the figure. This will be explained with reference to FIG. In this embodiment, the microcomputer of the main control board 100 first initiates data transmission processing for the entire system, and then data transmission is repeated between the system microcomputers in a chain.

In other words, the microcomputer 110 first
When EL is set to a high level H and data is transmitted, the data is received by the microcomputer 310 of the optical system control board 300. microcomputer 310
When it receives the data, it executes the interrupt processing described later in response to the interrupt request signal INTSR generated internally, processes the received data, and sends its own internal data to the main control board. It is transmitted to the microcomputer 110. Upon receiving this data, the microcomputer 110 of the main control board executes interrupt processing to be described later in response to the interrupt request signal INTSR, processes the received data, and outputs L to the output port SEL. , its own internal data, in turn to the microcomputer 210 of the operating board. When the microcomputer 210 receives the data,
In response to the interrupt request signal INTSR, it executes an interrupt process to be described later, processes the received data, and transmits its own internal data to the microcomputer 110 of the main control board.

By repeating the above operations, the main control board 10
0. Transmission and reception of data is repeatedly executed in order between the optical system control board 300 and the operation board 200.

The transmitted data is used to manage the control of the entire system, but is also used to detect abnormalities such as runaway of microcomputer programs on each control board.

The operations of each microcomputer mainly related to communication control will be explained below. 6a, 6b and 6c show the operation of the microcomputer 110 of the main control board, and FIGS. 7a and 7b show the operation of the microcomputer 210 of the operation board 200. In addition, the microcomputer 3 of the optical system control board
The communication-related operations of 10 are the same as those of the microcomputer 210 of the operation board, so illustration is omitted.

First, with reference to FIG. 6a, the microcomputer 110
6. After performing initialization (not shown), first, in step 1, the output port SEL is set to high level H, and then in step 2, internal data is sent to the B unit, that is, the optical system control board 300. Then, in step 3, interrupts are enabled when data is received.

When the above processing is completed, the main processing routine in step 4 is repeatedly executed to perform various controls necessary for the normal operation of the copying machine.However, even if the main processing routine is being executed, Then, when the serial I10 circuit B1 receives data, the reception interrupt request signal I
Since the NTSR has occurred and interrupts have been enabled in step 3, the process shown in FIG. 6b is immediately executed as the interrupt process in response. Incidentally, when a timer described later times out, a timer interrupt request signal is generated, and in response to the timer interrupt request signal, the timer interrupt process shown in FIG. 6c is immediately executed.

The reception interrupt processing shown in FIG. 6b will be explained.

In step 5, the state of the output port SEL is checked. If SEL is not at the high level H, step 6 is executed, the operation of timer B3 is stopped, and its count value is cleared to O.

In step 7, the received data stored in the receiving register of the serial 170 circuit B1 is processed, the type of the data is identified, and the data is stored in a memory at an address determined according to the type.

In step 8, the state of the output port SEL is checked again. If SEL is H, proceed to step 9, otherwise proceed to step 12.

If data transmission with the optical system control board 300 was performed in the previous process, in step 9, the output port S
Switch EL to L. Furthermore, if data transmission with the operation board 200 was performed in the previous process, step 12 is executed and the output port SEL is switched to H.

After step 9, proceed to step 10, and transfer the 1-byte data prepared in advance to the C unit, that is, the operation board 2.
Send to 00.

In step 11, timer B3 initialized in step 6
Start.

After step 12, the process proceeds to step 23, in which 1 byte of data prepared in advance is sent to the B unit, that is, the optical system control board 300.

After each step 11 or 13 is executed, the interrupt process is terminated and the process returns to the process shown in FIG. 6a. Main control board 1
There is a large number of data that 00 sends to the optical system control board 300 and the operation board 200, and each time the process of step 16 or step 20 in FIG. 6b is executed,
Bytes are sent in sequence.

As shown in FIG. 5, the main control board 100 repeatedly transmits data to the optical system control board 300 and the operation board 200 at substantially regular intervals. , main control board 10
Immediately upon receiving data from 0, the operation board 200
data is sent back to the main control board 100. Therefore, there is no major change in the time required to execute the program during that time, so the main control board 100
00, then main control board 100
The time Ttr until the terminal receives data from the operation board 200 is approximately constant.

Step 11 in FIG. 6b is executed every time the microcomputer 110 of the main control board sends data to the operation board 200, and step 6 is executed when the microcomputer 110 receives data from the operation board 200. Therefore, timer B3 transmits data from the operation board 200 to the main control board 100 after the main control board 100 sends the data to the operation board 200.
Count the time until it is received.

When starting timer B3 in step 11, a predetermined time is set in timer B3.
This is set to a value slightly larger than the normal time Ttr from when the main control board 100 sends data until it receives data from the operation board 200.

Therefore, normally, step 6 is executed before the timer B3 counts the time Ttr, and the timer B3 does not time out. However, due to some abnormality in the operation of the microcomputer 210 on the operation board, When runaway occurs, timer B3 is activated before microcomputer 110 receives data from operation board 200.
counts the time Ttr and times out. In that case,
A timer interrupt request is generated, and in response, microcomputer 110 executes the timer interrupt process shown in FIG. 6c.

Referring to FIG. 6c, in this timer interrupt processing, first, in step 14, O (L level) is output to the output port RES of the microcomputer 110, and in step 15, 0 is output to the output port ABN.

That is, the output port RES of the microcomputer 110
When 0 is output to , an L level is applied to the reset terminal of the microcomputer 210 on the operation board via the buffer Gld and the OR gate G 2 a shown in FIG. In that case, microcomputer 210 is inhibited from operating and all of its output ports are set to high impedance.

In that state, all loads connected to the output port are
The structure is such that the electricity is cut off.

In this embodiment, a large number of display devices included in the display unit 220 are divided into a plurality of rows and columns and connected in a matrix, and are connected to designated rows corresponding to scanning signals generated by the microcomputer 210. Dynamic display control is performed so that only the display is lit and designated lines are sequentially switched, but when the microcomputer 210 is stopped, power to all the displays is cut off. Therefore, when the main control board 100 detects an abnormality in the operation board 200, all the displays on the operation board 200 are turned off except for the abnormality indicator LED.

In step 15, when the microcomputer 110 of the main control board outputs 0 to the output port ABN, the indicator LED is energized via the transistor provided on the operation board 200, and lights up to indicate the occurrence of an abnormality. .

Therefore, in this embodiment, when an abnormality occurs on the operation board 200, only the display LED that indicates the abnormality lights up.
All other displays are turned off. In that case, since power is cut off to the display devices other than the LEDs, there is no risk that the display devices will be destroyed due to runaway of the microcomputer 210.

Next, the operation of the microcomputer 210 on the operation board will be described with reference to FIGS. 7a and 7b.

In normal processing, after initialization (not shown) is performed, an interrupt for data reception by the serial I10 circuit B1 is permitted in step 21, and the process proceeds to step 22. Step 22
Now, the display unit 220 provided on the operation board 200
Dynamic display control.

Key switch matrix 240 status reading control.

Executes each process of dimming control of the exposure lamp and temperature control of the fixing heater.

If interrupts are permitted in step 21, an interrupt request signal is generated when data from the main control board 100 is received, and in response, the reception interrupt process shown in FIG. 7b is executed.

In this reception interrupt processing, first, in step 31, subsequent reception interruptions are prohibited, in step 32, the received data is processed, and in step 33, the data on the operation board 200 is transferred to the A unit, That is, the main control board 100
Send to. When these processes are completed, step 7a
Return to the main routine processing shown in the figure.

That is, when data from the main control board 100 is received, the main control board 100 immediately responds to the data.
The data on the operation board 200 is returned to 0.

[Effects] As described above, according to the present invention, when a runaway occurs in a control device such as a microcomputer that controls a display group that is dynamically driven, the abnormality can be detected and displayed, and the abnormality can be detected and displayed. If this occurs, a large number of indicators connected in a matrix can be protected from destruction due to excessive current.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an electrical component of the copying machine shown in FIG. 2. FIG. FIG. 2 is a front view showing the structure of a mechanical section of a copying machine of one type that implements the present invention. FIG. 3 is a plan view showing the appearance of an operation board provided in the copying machine shown in FIG. 2. FIG. FIG. 4 is a block diagram showing the internal configuration of each microcomputer shown in FIG. 1. FIG. 5 is a flowchart showing the procedure of data transmission between the plurality of control boards shown in FIG. 6a, 6b, and 6c are flowcharts outlining the operation of the microcomputer 110 of FIG. 1. FIG. 7a and 7b are flowcharts showing an outline of the operation of the microcomputer 210 of FIG. 1. FIG. 1: Contact glass 2: Photosensitive drum 4: Eraser 30: Optical scanning system 100: Main control board (master control unit) 110.210.3], 0:
Microcomputer 110: (Second control means) 210: (First control means) 120: High voltage power supply unit 150: RAM 195: Reset IC 200
: Operation board (slave control unit) 220: Display unit 230: Display control circuit 240: Key switch matrix 250: Lamp control circuit 260: Heater control circuit 300: Optical system control board (second control unit) 3
2 0: RAM 330.340: Motor control circuit B1 Digital I10 circuit B3: Timer circuit B) Etc. Figure 7a Figure b Figure Procedure amendment (method) % formula % 2. Title of the invention 3. Case of the person making the amendment Relationship with address office equipment abnormality display device

Claims (1)

Scope of Claims: A slave control unit including a first control means and a plurality of display means connected in a matrix whose display is controlled by the first control means; and a control unit independent of the first control means. In the abnormality display device for office equipment, the abnormality display device includes: a master control unit that controls the entire device including the slave control unit; When the master control unit detects an abnormality in the slave control unit, applying a stop signal to the slave control unit to stop the first control means and de-energize the display means, An abnormality display device for office equipment, characterized in that the abnormality display means is energized.